1. Field of the Invention
The present invention concerns a user-manipulatable mechanism which is to be attached to a feminine sanitary napkin to allow for an optional formation of a contour in said napkin, which contour is to be interposed between the labia majora in order to achieve a tighter fit between said napkin and the urogenital area so as to enhance efficient menstrual absorption of menstrual exudate.
2. Description of the Prior Art
Most, if not all, presently commercially used standard feminine sanitary napkins or pads comprise a multilayered flat pad construction, including at least a fluid absorbent core, a fluid permeable cover, and a fluid-impermeable backing. In addition, most, if not all, commercially-used pads have adhesive means to secure said pads to the undergarment of the wearer.
The class of feminine sanitary napkins is designed to possess three major attributes: (a) efficient absorbency, (b) a discreet design, and (c) comfort wear. However, as is well known to those skilled in the art, these attributes are extremely difficult to achieve within a given design of one and the same pad, as they are in mutual conflict: the more the desired absorbency attributes, the thicker the absorbing core, and, consequently, the less discreet and comfortable, and vice versa. It is therefore not too uncommon to find pads manufactured in a variety of thicknesses and shapes by leading commercial brands.
A number of approaches which have been proposed to solve this inherent attribute conflict in pad design has been within a class of napkins which will herein be called "contoured napkins"-- a nomenclature loosely referring to napkins which depart from the flat construction described above. Indeed, contoured napkins have, in concept, two advantages: (a) they increase the absorbing core material while maintaining discreetness, as the extra material is positioned interlabially, and (b) they occlude menstrual exudate prior to egress and consequent forbidding staining. However, none of these approaches appear to be satisfactory for reasons which will be explained in the following brief review of a representative sample of approaches:
A number of pads have been suggested which comprise of two parts, either removable or built in. Thus, for example, U.S. Pat. Nos. 2,662,527, 3,183,909, 3,406,689, 3,528,422, and 4,079,739-- all typically have a primary pad comprising absorbent material, and a secondary pad, usually of a lesser thickness and face area than the primary pad, to be inserted interlabially by the wearer and partly into the vestibule of said wearer. All of these pads are designed to achieve greater absorbence. However, they all suffer from one common disadvantage: uncomfortability. Their lack of comfort is due to their geometries which do not respect the urogenital female anatomy.
Another set of pads has been suggested characterized by a ridge-like construction to be interposed interlabially. U.S. Pat. Nos. 3,865,112, 3,983,873 and 4,046,147 are examples thereof. Since these geometries are uniform along the longitudinal axis, they are extremely irritable to the wearer over prolonged periods of time, as they press against either the clitoris or the buttocks of the wearer, or both, thus causing chafing and abrasion.
Another set of napkins, representative of which are U.S. Pat. Nos. 3,092,109 and 3,121,427, concerntrates on bypassing the uncomfortability of interlabial pad insertion by including a raised element at the distal end of the pad to be seated between the wearer's frenulum and rectum to effect a "damming" action deterring rearward leakage of menses-- which is particularly effective when wearer is in supine position. A related napkin attending to the problem of rearward seepage is U.S. Pat. No. 4,536,181, which although rather different from the aforementioned napkins, features a shield which extends rearwardly to provide protection for the wearer during sleeping hours. However, inasmuch as these napkins attend to backward leakage they are much less effective with respect to forward seepage and leakage, in addition to being of questionable comfort to the wearer.
An approach which attempts to overcome these aforementioned problems is exemplifed in U.S. Pat. Nos. 4,631,062 and 4,673,403 where a labial pad is proposed with a raised profile in the posterior region of the pad intended for interposition within the vestibule of the wearer in order to achieve maximum occlusion of menstrual exudate while allegedly offering comfort due to its self-conforming attributes. While no explicit mention is made of how said pad is more self-conforming than any other contoured pad, a major disadvantage of U.S. Pat. No. 4,631,062 is the inability of the user to place the pad properly, a disadvantage acknowledged by the patentee who consequently coassigned a patent named "Method and Pad Allowing Improved Placement of Catamenial Device". This latter patent '403 provides "indicating means" for the proper placement of feminine pads. However, according to the patentee, even these means are not entirely "fool proof" and it is suggested that where there are women with anatomical differences, individualized and accurate placement can be achieved by inspecting the pattern of most staining in the previously used pad and making the proper adjustment in placement.
Review of the various appraches offered to solve these aforementioned problems reveals a consistent failure to acknowledge and address one maj/r parameter of the female menstrual cycle, namely, its intra-individual variability over and above inter-individual variability: Within one and the same menstrual cycle, there appears to occur variability not only with respect to heaviness of the menstrual flow, but also with respect to its direction as exemplified in Table 1 below, where staining patterns are shown as a function of day within the cycle, activity of the wearer, and other factors such as degree of tissue swelling.
TABLE 1 __________________________________________________________________________ portion of day in cycle: napkin 1st day 2nd day 3rd day __________________________________________________________________________ dors. 7 + 6 ++ + + 5 ++ ++ ++ + + 4 ++ + ++ + ++ 3 ++ + ++ + 2 ++ ++ ant. 1 ++ + activity: SED ACT SUP SED ACT SUP SED ACT SUP __________________________________________________________________________ Areas of menstrual staining on a feminine napkin as a function of activit (SED = sedentary, ACT = active, SUP = supine), and day in the menstrual cycle (1st, 2nd, and 3rd). Abbreviations: dors. = dorsal end of napkin, ant. = anterior end of napkin, ++ = heavy staining, + = light staining
Such immense variability calls for a flexible approach in pad design. As our research indicates, from a sample of 25 subjects, 19 women who preferred an experimental contoured pad during hours of heavy menstrual flow within the cycle, or for the night hours, when in supine position, also preferred a flat, non-contoured pad when their menstrual flow was lighter (three additional subjects preferred a contour throughout the whole menstrual cycle). Thus, inasmuch as an interlabial contour is less comfortable to the wearer than a flat pad, said wearer may prefer efficient absorbence of menses over comfort when her menstrual flow becomes lighter. Furthermore, and most importantly for those skilled in the art of feminine napkin design, the direction of menstrual seepage varies as mentioned above and exemplified in Table 1: some menstrual exudate tends to seep forward towards the clitoris and pubis, some seeps rearward, and some other seeps in the middle, opposite the vestibule, and soon leaks sideways toward the groin. These flow patterns furthermore depend on the condition of the swelling of the urogenital area during various periods throughout the menstrual cycle, on the type of activity in which the wearer engages, such as sports, sedentary, supine, etc., and on anatomical differences. All these factors affect the desired placement of the contoured pad for an effective occlusion of the menstrual exudate, which, in turn, calls for a variety of napkin designs to accommodate this large variability among napkin users.
Thus, there has yet to be devised a feminine napkin or pad, which offers featural flexibility to accommodate all the aforementioned requirements, while at the same time overcomes the disadvantages of lack of comfort and inefficient absorbence. The present invention fulfills that need.